Relay sockets for an electrical connector installed on an installation structure, such as a panel, are used for electrically connecting a large number of electrical relays side-by-side in a dense arrangement.
A conventional relay socket includes a base that is secured to the installation panel by, for example, bolts, screws, or nuts. Due to the number of small metallic parts to be aligned and tightened to the panel, the installation of this type of relay socket is time consuming and requires the use of specific tools, such as dynamometric equipment for verifying the fixations and metallic keys for tightening and removing the screws. Moreover, the access to the tightening elements with such tools is generally at a rear side of the panel, close to the wiring, and thereby risks damaging other cables during installation. The use of bolts or screws for fixing the socket also poses the problem that the screws become loose with time when subject to shocks and vibrations, such in aircraft applications, which requires time-consuming regular maintenance for verifying the state of all tightening elements.
Other types of relay sockets have been proposed to facilitate the installation of the socket on the panel.
A relay socket with a plurality of integral locking members for attaching and locking the relay socket to a structure surface, such as a panel, without the use of attachment hardware such as nuts or screws has been proposed in UK patent application GB 2462524 A. The locking members are stepped conical resilient members that pass through holes in the structure surface and then pass through holes in the relay, locking the relay socket to both the structure surface and the relay.
Another configuration of a panel-mounted connector for relays is described in UK patent application GB 2310550 A. The panel supports several relay bases into which relays can be plugged and includes elongated apertures with slots down each side. Each relay base is retained, on the rear side of the panel, by two resilient beams having outwardly-projecting catches that project through the apertures and overlap the front surface. Lugs on opposite sides of each base engage in the slots to prevent movement of the bases along the apertures. The relays are secured on the bases by screws that engage screw holes in the bases aligned with the slots. When mounted, a part of each relay lies between the catches, thereby preventing them from being displaced inwardly sufficiently to clear the edges of the aperture.
Although the above configurations reduce the number of screws required for installing the relay socket, an access to both front and rear sides of the installation panel is still required in order to mount and remove both the socket and the relay from the panel. Moreover, the panel must be provided with dedicated holes/slots for fixing the socket.
United States patent application publication US 2002/0142643 A1 describes a relay socket attachable to a cutout in a panel. The relay socket includes at least one rocker beam element at one side of the base and at least one active snap element at the opposite side of the base. The socket is inserted into place by engaging the rocker beam element on one side of a cutout in a panel and pivoting the active snap element toward the opposite side of the cutout so that it engages the opposite side of the cutout, moves inwardly, and is inserted into the cutout in the panel. When inserted into the cutout, the active snap element moves outwardly to engage the opposite side of the cutout and the elements cooperatively hold the socket onto the panel. Since the relay is plugged to the side of the base provided with the rocker beam element and the active snap element, this connection arrangement still requires access to both sides of the panel for mounting as well as for removing the relay and the base. Moreover, in order to remove the socket from the panel, access to both sides of the panel is necessary so as to press the snap element from one side while the base is simultaneously rotated from the other side of the panel for disengaging the rocker beam element.